(1) Field of the Invention
The present invention relates generally to a control apparatus for an internal combustion engine and a control method therefor. The present invention relates particularly to the control apparatus for the internal combustion engine and the control method therefor which are capable of improving a fuel economy and capable of suppressing a torque shock to be developed when an engine driving region is transferred to a partial cylinder halt (reduced cylinder) driving region in which operations of intake and exhaust valves of a given part of cylinders of the engine mounted in an automotive vehicle are temporarily stopped (stopped in closed states) (so-called, a cylinder halt).
(2) Description of Related Art
A Japanese Patent Application Publication No. Heisei 10-82334 published on Mar. 31, 1998 exemplifies a previously proposed engine control apparatus which can perform the cylinder halt described above. In the above-described Japanese Patent Application Publication, the control apparatus includes: a hydraulic cylinder halt mechanism configured to switch between a drive mode in which all of a plurality of engine cylinders are operated and another drive mode in which operations of the given part of the plurality of engine cylinders are halted (the cylinder halt drive is carried out); a solenoid valve configured to control a supply or an interruption (cut off) of a hydraulic pressure to the hydraulic cylinder halt mechanism; and a control unit configured to control a drive of the solenoid valve, the control unit setting a drive timing of the solenoid valve on the basis of engine driving condition detecting means.
Thus, the cylinder halt mechanism is operated at an appropriate timing to perform the cylinder halt and to release the cylinder halt.